The first objective is to establish an animal model of allergic aspergillosis in non-human primates. Monkeys are sensitized with A. fumigatus to produce precipitating antibody. Human serum rich in IgE antibody to A. fumigatus is infused and the animals challenged with A. fumigatus aerosol. Changes in lung tissue are determined by light microscopy, immunofluorescence and electron microscopic examination of serially obtained open lung and transbronchial biopsied tissue. Bronchial lavage is performed and lavage fluid and cells evaluated for immunoglobulin and protein content, enzyme activity and evidence of cell mediated immunity. The same sensitization will be done in the monkey skin with serialbiopsies. The second major objective is to continue studies on the epidemiology of allergic aspergillosis. In order to determine whether the increased incidence of this disease in Great Britian is due to differences in the atmospheric burden of A. fumigatus, air sampling in St. Louis will be carried out with an Andersen sampler and compared to Great Britain. Individuals with a particularly heavy exposure to A. fumigatus, namely organic farmers, will be evaluated for sensitivity to A. fumigatus by skin testing and precipitin testing.